What class of amplifier has the most high definition sound ?

The question was about the *class* of amplifier. And -- if cost i no object and all other variables held constant, class-A, no question.  But it has many downsides, mostly size, heat and cost int he real world.
For small signals anyone who doesn't design class-A is crazy. For big power amplifiers there are many trade-offs. Note there are also sliding scales.
Class D, an entirely different type of "class" has huge potential but still needs refinement. Modern GaN is already helping.
But among A, AB, C it is clearly A.  That said i always design high bias AB for bog amps.

Only opinion:
High efficiency speakers with a First Watt amp.  

Ok guys, my question was focused in experience and sensitivity to pure sound.
Class A, A/B, D ? High definition or pure sound are subjective concepts.

I didn’t ask for brand or speakers quality. I said compatible system!

Thanks you all.

"They" say that SET amplifiers are the best but since I have no experience with them I cannot confirm or deny it. But "they" say lots of things that may or may not be nebulous. In general I consider vacuum tube amps to be superior for audio reproduction but others swear by solid state. I suspect it all comes down to individual ears as I’ve proffered before.....different folks hear differently just like how some folks can see better than others. Perhaps one day we can all be able to say "I see the light."

That is not  clear  cut at all, a SET tube amp with very efficient speakers may have the best purist  midrange,  and a big solid state amp  may have the best dynamics or Bass. The speaker 
and type of music too come into play.  The correct answer is
No amplifier is the best under all circumstances .